Edexcel GCSE Geography: River Environments

Key Takeaways for GCSE Geography: River Environments

1. The Hydrological Cycle

• Closed System: Fixed amount of water recycled through stores and transfers.
  • Stores: Atmosphere (water vapour), land (ice, lakes, soil), sea (95% of Earth’s water).
  • Transfers: Evaporation, transpiration, precipitation, infiltration, overland flow, groundwater flow.
• Example: Solar energy drives evaporation from the sea → condensation forms clouds → precipitation transfers water to land.
• Tip: Sketch the cycle, labelling stores (boxes) and transfers (arrows). Use the acronym “SIP COW” for transfers: Solar energy, Infiltration, Precipitation, Condensation, Overland flow, Water flow.

2. Drainage Basins

• Watershed: Boundary separating neighbouring basins.
• Channel Network: Surface/underground channels transporting water.
• Factors Affecting Runoff:
  • Rock type (impermeable = more runoff), relief (steep slopes = faster flow), land use (urbanisation = reduced infiltration).
• Example: Basin A (dense channel network) responds faster to rainfall than Basin B (sparse network).

3. Hydrographs & River Regimes

• River Regime: Annual discharge variation (e.g., monsoon rivers peak in wet season).
• Storm Hydrograph: Shows discharge during a rainstorm.
  • Lag Time: Delay between peak rainfall and peak discharge.
    • Formula: Lag Time=Peak Discharge Time−Peak Rainfall TimeLag Time=Peak Discharge Time−Peak Rainfall Time
  • Factors Reducing Lag Time: Deforestation, steep slopes, intense rainfall.
• Discharge Unit: m3/s (cumecs)m3/s(cumecs)
• Exam Tip: Compare hydrographs for permeable vs. impermeable basins.

4. River Processes

• Erosion:
  • Hydraulic action (force of water), abrasion (rocks scraping bed), attrition (rocks collide), corrosion (chemical dissolve).
• Transportation:
  • Traction (rolling boulders), saltation (bouncing pebbles), suspension (fine sediment), solution (dissolved minerals).
• Deposition: Occurs when energy drops (e.g., river enters flat land).
• Mass Movement: Slumping (saturated soil collapses) and soil creep (slow movement).

5. River Landforms

• Upland (Erosion):
  • V-shaped Valley: Vertical erosion + mass movement.
  • Waterfall: Forms over resistant rock; plunge pool erodes softer rock below.
• Lowland (Deposition):
  • Meanders & Oxbow Lakes: Lateral erosion (outside bend) + deposition (inside bend).
  • Floodplains & Levees: Built by repeated flooding (coarse material deposited first).
• Exam Tip: Draw annotated diagrams for waterfalls and meanders (Figure 1.6 & 1.7).

6. Water Demand & Management

• Global Demand: Doubles every 20 years due to population growth, agriculture, and industry.
• Case Study – UK: South-east faces deficit (high population, low rainfall); water transferred from north-west.
• Water Pollution Sources: Agricultural runoff (fertilisers), industrial waste, untreated sewage.
• Treatment Processes: Sedimentation, filtration, chlorination.
• Dams (Hard Engineering):
  • Pros: Flood control, HEP, regulated supply.
  • Cons: Habitat loss, siltation, displacement (e.g., Three Gorges Dam).

7. Flooding & Control

• Causes: Heavy rain, snowmelt, deforestation, urbanisation (reduces infiltration).
• Management:
  • Hard Engineering: Dams, embankments (effective but costly).
  • Soft Engineering: Afforestation, wetlands (sustainable but slow).
• Case Study: Bangladesh uses embankments + flood warnings.

8. Exam Techniques

• Case Studies: Revise one water storage project (e.g., Kielder Reservoir) and one flooding event (e.g., 2007 UK floods).
• Diagrams: Practise cross-sections (V-shaped vs. U-shaped valleys) and annotated landforms.
• Maths Skills: Calculate lag time using hydrograph data.
• Key Terms: Define terms like aquifer (permeable rock storing water) and levee (natural embankment).

50 GCSE Geography Questions

Section A: The Hydrological Cycle

1. What is the hydrological cycle?
2. Name three stores of water in the hydrological cycle.
3. Which store holds 95% of the Earth’s water?
4. Define transpiration.
5. How does solar energy drive the hydrological cycle?
6. What is condensation?
7. Explain the term infiltration.

Section B: Drainage Basins

8. What is a watershed?
9. How does rock type affect surface runoff?
10. Why might Basin A (dense channel network) respond faster to rainfall than Basin B?
11. Define channel network.
12. What is meant by overland flow?
13. How does urbanisation increase surface runoff?

Section C: Hydrographs & River Regimes

14. What is a river regime?
15. Define lag time in a storm hydrograph.
16. Calculate the lag time if peak rainfall occurs at 10:00 and peak discharge at 14:00.
17. How does deforestation affect lag time?
18. What is base flow?
19. Name three factors that increase lag time.
20. What unit is river discharge measured in?

Section D: River Processes

21. Name the four types of erosion.
22. Describe hydraulic action.
23. What is saltation?
24. How does deposition occur?
25. Explain mass movement in river valleys.
26. Name two types of mass movement.

Section E: River Landforms

27. How is a V-shaped valley formed?
28. Explain the formation of a waterfall.
29. What is a gorge?
30. Describe how meanders develop.
31. How does a river cliff form on the outside bend of a meander?
32. What is a floodplain?
33. How are levees formed?

Section F: Water Demand & Management

34. Why has global water demand doubled every 20 years?
35. Name two causes of water pollution.
36. How does agriculture contribute to water pollution?
37. What is an aquifer?
38. Describe chlorination in water treatment.
39. Give one advantage and one disadvantage of dams.
40. Why does the UK transfer water from the north-west to the south-east?

Section G: Flooding & Control

41. What causes flooding?
42. How does urbanisation increase flood risk?
43. Define hard engineering in flood control.
44. Give two examples of soft engineering.
45. How do wetlands reduce flooding?
46. Why is flood prediction challenging?

Section H: Case Studies & Skills

47. Name a water storage project and its impacts.
48. Describe one method of investigating river channel characteristics during fieldwork.
49. Draw a labelled cross-section of a meander (note: diagram required).
50. Explain how climate change could affect river regimes.

Detailed Answers

Section A: The Hydrological Cycle

1. Hydrological cycle: A closed system where water is continuously recycled between stores (e.g., sea, atmosphere) via transfers (e.g., evaporation, precipitation).
2. Three stores: Atmosphere (water vapour), land (ice, lakes, groundwater), sea.
3. 95% of water is stored in the sea.
4. Transpiration: Plants release water vapour into the atmosphere.
5. Solar energy drives evaporation from the sea and land surfaces.
6. Condensation: Water vapour cools and turns into liquid droplets (forms clouds).
7. Infiltration: Water soaks into the soil.

Section B: Drainage Basins

8. Watershed: Boundary separating neighbouring drainage basins.
9. Impermeable rock (e.g., granite) reduces infiltration, increasing surface runoff.
10. Basin A has more channels to transport water quickly, reducing lag time.
11. Channel network: System of surface/subterranean channels transporting water.
12. Overland flow: Precipitation flowing over the ground into rivers.
13. Urbanisation (e.g., concrete) reduces infiltration, increasing runoff.

Section C: Hydrographs & River Regimes

14. River regime: Annual variation in a river’s discharge due to climate and basin characteristics.
15. Lag time: Delay between peak rainfall and peak discharge.
16. Lag time calculation:
    Lag Time=14:00−10:00=4 hoursLag Time=14:00−10:00=4hours
17. Deforestation reduces interception, speeding up runoff and shortening lag time.
18. Base flow: Normal day-to-day discharge from groundwater.
19. Factors increasing lag time: Permeable rock, gentle slopes, afforestation.
20. Discharge unit: m3/s (cumecs)m3/s(cumecs).

Section D: River Processes

21. Erosion types: Hydraulic action, abrasion, attrition, corrosion.
22. Hydraulic action: Force of water breaking rock.
23. Saltation: Pebbles bounce along the riverbed.
24. Deposition: Occurs when river energy drops (e.g., on flat land).
25. Mass movement: Weathered material moves downhill due to gravity (e.g., slumping).
26. Two types: Slumping, soil creep.

Section E: River Landforms

27. V-shaped valley: Vertical erosion cuts downwards; mass movement widens sides.
28. Waterfall: Forms where hard rock overlies soft rock. Soft rock erodes (hydraulic action), creating a plunge pool. Overhang collapses, retreating upstream.
29. Gorge: Steep-sided valley formed as a waterfall retreats.
30. Meanders: Lateral erosion on outer bends (fast flow) and deposition on inner bends (slow flow).
31. River cliff: Fast-flowing water undercuts the outer bend.
32. Floodplain: Flat land formed by repeated flooding and deposition.
33. Levees: Coarse sediment deposited along riverbanks during floods.

Section F: Water Demand & Management

34. Demand growth: Population rise, industrialisation, agricultural irrigation.
35. Pollution causes: Agricultural runoff (fertilisers), industrial waste.
36. Agriculture: Fertilisers/pesticides enter rivers via runoff; slurry contaminates groundwater.
37. Aquifer: Permeable rock storing groundwater (e.g., chalk).
38. Chlorination: Adding chlorine to kill bacteria in water treatment.
39. Dam pros/cons:

• Pros: Flood control, HEP.
• Cons: Habitat loss (e.g., Three Gorges Dam displaced 1.3 million people).

40. UK water transfer: South-east has high demand/low rainfall; north-west has surplus.

Section G: Flooding & Control

41. Flood causes: Heavy rain, snowmelt, deforestation, urbanisation.
42. Urbanisation: Impermeable surfaces increase runoff, reducing lag time.
43. Hard engineering: Structures like dams/embankments to control floods.
44. Soft engineering: Afforestation, wetland preservation.
45. Wetlands: Absorb floodwater, acting as temporary stores.
46. Prediction challenge: Flood severity and timing vary unpredictably.

Section H: Case Studies & Skills

47. Kielder Reservoir (UK):

• Aims: Water supply, tourism.
• Impacts: Flooded farmland, habitat loss.

48. Fieldwork method: Measure channel width/depth; calculate cross-sectional area.
49. Meander cross-section (diagram): Label river cliff (outer bend), slip-off slope (inner bend).
50. Climate change: More intense rainfall → shorter lag time → increased flood risk.

50 GCSE Coastal Environments Questions

Section A: Coastal Systems & Processes

1. What is meant by the coast being an ‘open system’?
2. Compare constructive and destructive waves in terms of wavelength and beach impact.
3. List the four erosion processes (acronym HACA) and briefly describe each.
4. How does weathering accelerate coastal erosion?
5. Explain the role of mass movement in coastal erosion.

Section B: Erosional Landforms

6. How do headlands and bays form? Use an example in your answer.
7. Describe the formation of a wave-cut platform.
8. Outline the stages in the development of a stack from a headland.
9. What is the difference between a concordant and discordant coastline?
10. Name a UK example of a discordant coastline.

Section C: Depositional Landforms

11. How are sandy beaches different from shingle beaches?
12. Explain the role of wave refraction in forming curved beaches.
13. Describe how a spit forms. Use a labelled diagram in your answer.
14. What conditions are needed for a bar to form?
15. Name a UK example of a spit and a bar.

Section D: Factors Affecting Coasts

16. How does geology influence cliff shape?
17. Why are sand dunes stabilised by vegetation? Name a plant species involved.
18. Contrast submergent and emergent coastlines with examples.
19. Explain why Miami is vulnerable to sea-level rise.
20. How does human settlement increase coastal erosion risks?

Section E: Coastal Ecosystems

21. State the four conditions required for coral reef growth.
22. How does coral bleaching occur?
23. Describe two adaptations of mangrove trees to their environment.
24. Why were areas with mangroves less affected by the 2004 tsunami?
25. What is zonation in a salt marsh?

Section F: Coastal Management

26. Compare hard and soft engineering strategies.
27. What are the advantages and disadvantages of groynes?
28. Explain how managed retreat creates salt marshes.
29. Why might local residents oppose managed retreat?
30. What is a conflict matrix? How is it used in coastal planning?

Section G: Case Studies

31. Describe the causes of rapid erosion on the Holderness Coast.
32. How has Mappleton been protected from erosion? What are the downsides?
33. Outline the Coastal Zone Policy in Bangladesh.
34. How has St Lucia protected its coral reefs?
35. Why is the Isle of Arran an example of an emergent coastline?

Section H: Skills & Applications

36. Draw an annotated diagram of longshore drift.
37. How would you use a quadrat to measure pebble size in a beach transect?
38. Calculate the rate of erosion if a cliff retreats 10 metres in 5 years.
39. Explain why destructive waves have a stronger backwash than swash.
40. Describe how to plot a conflict matrix for stakeholders.

Section I: Exam-Style Questions

41. “Coastal erosion is inevitable.” Discuss this statement using examples. (6 marks)
42. Assess the effectiveness of hard engineering strategies. (6 marks)
43. Explain the economic and environmental value of coral reefs. (6 marks)
44. Evaluate the threats to mangrove ecosystems. (6 marks)
45. “Human activity is the greatest threat to coasts.” To what extent do you agree? (9 marks)

Section J: Definitions & Key Terms

46. Define: swash, backwash, longshore drift.
47. What is a ria? Give an example.
48. What is meant by ‘beach replenishment’?
49. Define ‘attrition’ in coastal processes.
50. What is a ‘relict cliff’?

Detailed Answers

1. Open system: The coast receives inputs (e.g., sediment from rivers) and loses outputs (e.g., sediment to the sea). Example: Sediment from a river delta enters the system.
2. Constructive waves: Long wavelength, gentle slope, strong swash (builds beach). Destructive waves: Short wavelength, steep slope, strong backwash (erodes beach).
3. HACA:
   • Hydraulic action: Waves compress air in cracks.
   • Abrasion: Rocks scrape cliffs.
   • Corrosion: Dissolving rocks (e.g., limestone in acidic water).
   • Attrition: Rocks collide and break apart.
4. Weathering weakens cliffs (e.g., freeze-thaw breaks rocks), making erosion easier.
5. Mass movement (e.g., slumping) adds material to the base of cliffs for waves to erode.
6. Headlands & bays: Form when resistant rock (e.g., limestone) erodes slower than soft rock (e.g., clay). Example: Swanage Bay, Dorset.
7. Wave-cut platform: Waves erode a notch at the cliff base → cliff collapses → platform remains.
8. Cave → arch → stack → stump: Hydraulic action enlarges a crack into a cave. Erosion creates an arch, which collapses, leaving a stack. The stack erodes into a stump.
9. Concordant: Rocks parallel to coast (e.g., Lulworth Cove). Discordant: Rocks perpendicular to coast (e.g., Swanage Bay).
10. Discordant example: Dorset Coast, UK.
11. Sandy beaches: Formed by gentle waves sorting fine sediment. Shingle beaches: High-energy waves deposit larger pebbles.
12. Wave refraction bends waves into bays, depositing sediment in a curved shape.
13. Spit formation: Longshore drift moves sediment → coast changes direction → sediment deposited in sheltered water (e.g., Spurn Head).
14. Bar formation: Requires a bay with no major river. Example: Slapton Ley, Devon.
15. Spit: Spurn Head. Bar: Slapton Ley.
16. Cliff shape: Hard rock (e.g., granite) forms steep cliffs; soft rock (e.g., clay) forms sloped cliffs with slumping.
17. Vegetation (e.g., marram grass) binds sand with roots, preventing wind erosion.
18. Submergent: Drowned valleys (rias, e.g., Kingsbridge Estuary). Emergent: Raised beaches (e.g., Isle of Arran).
19. Miami: Built at sea level; faces flooding from rising seas (e.g., storm surges).
20. Settlement: Buildings increase weight on cliffs, speeding up mass movement.
21. Coral conditions:

• Water temperature > 18∘C18∘C.
• Depth <25m (light penetration).
• Saltwater.
• Clear water (no sediment).

22. Coral bleaching: Warmer water causes corals to expel algae, turning white.
23. Mangrove adaptations: Prop roots for stability, salt-filtering roots, floating seeds.
24. Mangroves absorbed tsunami energy, reducing wave impact.
25. Zonation: Plants like cordgrass (high salinity) grow in lower marsh; shrubs in upper marsh.
26. Hard engineering: Artificial structures (e.g., sea walls). Soft engineering: Natural methods (e.g., beach replenishment).
27. Groynes: Trap sediment (pros), but cause erosion downstream (cons).
28. Managed retreat: Allowing sea to flood land creates salt marshes (e.g., Abbots Hall Farm).
29. Opposition: Loss of homes/farmland; emotional attachment to land.
30. Conflict matrix: Grid showing stakeholder conflicts (e.g., tourism vs fishing).
31. Holderness erosion: Soft boulder clay + powerful NE waves erode coast at 1–2m/year.
32. Mappleton: Rock groynes and rip-rap (£2m) protect village but increase erosion southward.
33. Bangladesh: Planting mangroves to trap sediment and buffer storms (1.29m hectares reclaimed).
34. St Lucia: Zoning restricts fishing/tourism to protect reefs.
35. Isle of Arran: Raised beaches show past sea-level fall.
36. Longshore drift diagram: Show swash at wind angle (e.g., 45°) and backwash straight down.
37. Quadrat use: Place quadrat every 5m in a transect; measure pebble size (e.g., axis length).
38. Erosion rate: Rate=10 m5 years=2 m/yearRate=5 years10 m​=2 m/year.
39. Backwash strength: Destructive waves have short wavelengths, so water returns seaward rapidly.
40. Conflict matrix: Label rows/columns with stakeholders; use symbols (e.g., ● for strong conflict).
41. Erosion inevitability: Natural process, but humans can slow it (e.g., Holderness management).
42. Hard engineering: Effective short-term (e.g., sea walls) but costly and unsustainable.
43. Coral value: Tourism ($), fish habitats, coastal protection.
44. Mangrove threats: Aquaculture, pollution, deforestation.
45. Human threat: Yes (e.g., overfishing reefs), but natural factors (e.g., storms) also play a role.
46. Swash: Waves moving up beach. Backwash: Water returning down. Longshore drift: Lateral sediment transport.
47. Ria: Drowned river valley (e.g., Kingsbridge Estuary, Devon).
48. Beach replenishment: Adding sand/shingle to eroded beaches (e.g., Bournemouth).
49. Attrition: Rocks collide and become rounded/smaller.
50. Relict cliff: Inland cliff no longer eroded by sea (e.g., raised beach cliffs on Isle of Arran).